Silver Spring, Maryland -- The US Food and Drug Administration has recommended that patients who have implantable heart defibrillators with Riata and Riata ST leads should have X-rays or other imaging alternatives to check for abnormalities in the insulation surrounding the lead.
The manufacturer of the leads, St Jude Medical of St Paul, Minnesota, recalled them in November 2011 after reports of premature erosion of the silicone-polyurethane co-polymer insulation around the electrical conductor wires, also called insulation failure.
The company had stopped selling the leads in late 2010, but said that as of 2011, about 79 000 Riata leads remained implanted in patients in the US.
Insulation failure may cause some of the electrical conductors inside Riata leads to move within or move entirely outside the outer lead insulation, the FDA said in a 16 Aug news release. The lead may malfunction and lead to potentially life-threatening abnormal heart rhythms.
The FDA said its recommendation is supported by several studies that have demonstrated that routine imaging of the leads may detect previously unrecognised abnormalities with the insulation. The FDA is also cautioning against routine removal of leads without careful evaluation of benefits and risks to the individual patient.
"The majority of Riata and Riata ST leads, including those that show signs of electrical conductor migration or externalisation, continue to function normally and provide life-saving support for patients," said Jeffrey Shuren, director of FDA's Center for Devices and Radiological Health. "However, the agency does not have enough information to determine the frequency and timing of insulation failure in these leads. Therefore, the post-market surveillance studies will ensure that health care professionals and patients get the data they need to better guide clinical management decisions."
The FDA is also requiring St. Jude Medical to conduct three-year post-market surveillance studies to collect clinical data related to the potential for premature insulation failure in Riata and Riata ST leads.
While the current recommendations apply only to the Riata and Riata ST ICD and CRT-D leads, the FDA also is requiring St. Jude Medical to conduct post-market surveillance studies on its QuickFlex LV CRT leads, QuickSite LV CRT leads; Riata ST Optim and Durata ICD leads.
St Jude Medical voluntarily recalled and stopped selling its QuickSite LV CRT leads and QuickFlex LV CRT leads in April 2012. These devices were recalled due to insulation abrasion.